Mainly by reading the documentation and making comments. Stroscot is in "slow-burn" mode while the language is designed so any and all input will be taken into consideration. If you want to write docs yourself, just submit a pull request. Commit access is available for anyone with 2 or more accepted pull requests.
The license isn't set yet (WTFPL is just a placeholder) so for now please license your contributions under CC0.
The documentation is supposed to be inviting to people of all skill levels, so documenting items like how to get started, where to find key files, expectations, etc. are all contributions that will be accepted.